The present invention relates generally to vehicle wheel balancer and brake lathe systems, and in particular, to components configured to facilitate the centered mounting of vehicle wheels having a variety of hub pilot hole sizes and lug hole configurations on a vehicle wheel balancer spindle, as well as the centered mounting of a vehicle brake drum or brake rotor onto a brake lathe machine.
A variety of components are utilized to facilitate the centered mounting of vehicle wheels on a vehicle wheel balancer system, and the centered mounting of vehicle brake drums or brake rotors on brake lathes. Centering cones fitted over the spindle shaft of the wheel balancer or brake lathe system provide a center support sized to receive a corresponding hub pilot hole of the wheel, brake rotor, or brake drum. Due to the lack of standardization of hub pilot hole diameters on automobiles, there is a large range of hub pilot hole diameters which centering cones must encompass. A centering cone is configured with an axial bore of uniform diameter, sized to fit over the spindle shaft of the wheel balancer or brake lathe system. To accommodate as many wheels, brake rotors, or brake drums as possible, the outer surface of each cone is tapered to provide a frustoconical surface to receive the inner surface of a hub pilot hole.
It is known to those of ordinary skill in the balancer field that a lower included angle on a centering cone will provide for better centering of an associated wheel, brake rotor, or brake drum. However, to encompass the entire required range of hub pilot hole diameters which are commonly seen in the vehicle service industry with low-included angle centering cones, a greater number of centering cones is required. In order to ensure complete coverage of a range of pilot hole diameters, it is further desirable to provide for some degree of “overlap” in each centering cone. The “overlap” can be defined as the portion of each subsequent centering cone in a set which has the same range of diameters. Alternatively, this can be described as the situation where the major diameter of a centering cone is slightly larger than the minor diameter of the next larger centering cone in the set.
The total number of centering cones required to cover a specific range of hub pilot hole diameters is defined by the angle chosen for the conical taper, the length of the taper, and the amount of overlap desired between each centering cone in the set. Typical centering cones used with automotive service equipment have a single taper on each piece, and a minimum amount of overlap. From here on “taper” will be defined as having all the dimensions necessary to define a frustoconical portion of a cone: maximum diameter, minimum diameter, and the included angle.
Traditionally centering cones have been approximately 1.5″ to 2.0″ tall. This has been done to minimize the number of cones required to cover a desired range of pilot diameters. Current design trends in automotive wheels are producing many wheels with diameters inside the center bore that are smaller than the pilot diameter. For proper centering it is necessary for the centering cone to contact the wheel on the proper pilot diameter only. Not one of the alternate diameters inside the center bore. This is making it necessary to design centering cones that are shorter than in the past. Many cone manufacturers are releasing many short cones to cover these applications
One system for minimizing the number of centering cones required in a set is to utilize centering cones having two opposing tapers on the same unit. These centering cones are of unitary construction, having their maximum diameters centrally disposed, such that the cone is merely reversed on the spindle to switch from one taper to the other. In order to ensure complete coverage for the entire range of pilot hole diameters likely to be encountered during vehicle service, a significant amount of overlap is provided between tapers. However, it has been found that when cones are provide with relatively small included angles, i.e., low taper angles, and small differences in diameters, it becomes difficult for an operator to distinguish one cone from another. The typical method for selecting a suitable cone for use is to look at the pilot hole diameter of the wheel, brake rotor, or brake drum, and make an educated guess as to which cone is most suitable, A trial and error process then ensues until a suitable centering cone is found. Accordingly, it would be highly desirable to provide a method for selecting and identifying suitable centering cones for use in mounting a vehicle wheel, brake rotor, or brake drum on a rotating spindle of a balancer or lathe which does not require extensive trial and error.
Typically, to secure a vehicle wheel to a balancer spindle once it is centered on a centering cone, a flange plate is utilized in conjunction with a tension nut screwed onto the balancer spindle. A conventional flange plate consists of a rigid steel disc with a multitude of holes arranged in axially parallel equally-spaced sets surrounding a central pilot hole, such as shown in U.S. Pat. No. 5,665,911 to Warkotsch. Each set corresponds to a lug circle arrangement commonly found on vehicles, and is adapted to receive a mounting pin. The holes corresponding to different sets are typically identified by one or more forms if identifying indicia, such as shown in U.S. Pat. No. 5,987,761 to Ohnesorge. During use, a mounting pin is positioned in each hole on a flange plate corresponding to the lug circle for a wheel to be secured to a balancer spindle. The wheel is seated on a suitable centering cone on the balancer spindle, and the flange plate fitted onto the spindle. The flange plate is moved down the balancer spindle until each of the mounting pins engages a corresponding lug hole in the vehicle wheel, at which point the tension nut is threaded onto the balancer spindle, clamping the vehicle wheel between the balancer hub and flange plate while being centered by the cone.
An alternate design flange plate is shown in U.S. Pat. No. 6,619,120 to Hansen. This plate is made of a polymeric material and has some amount of radial compliance due to flexing of the plate and its fingers. This design will lack the durability of an adaptor made of hardened steel. Also the pins are either fixed to the plate or they must be placed in discrete locations on the plate thus requiring several plates to cover the desired range of vehicles.
Currently, several flange plates are required in order to cover the wide variety of lug hole configurations found on common vehicle wheels. Lug hole configurations may include four or more holes in a variety of diameters. Accordingly, a technician utilizing a vehicle wheel balancer is required to initially select a suitable flange plate having the proper lug hole spacing and configuration, and then to install the appropriate number of mounting pins in the corresponding holes before securing the vehicle wheel to the balancer spindle. This process must be repeated for each different vehicle wheel mounted on the balancer spindle, leading to a significant amount of time spent in selecting and setting up the appropriate flange plates. Accordingly, it would be highly desirable to provide a flange plate system which may be quickly adjusted to accommodate a wide variety of lug hole patterns, and which is tolerant of a degree of misalignment between the vehicle wheel lug hole pattern and the mounting pin placement to facilitate rapid securing of vehicle wheels to a balancer spindle.